Rotary straightening machine



Jan. 3l, 1967 l R. G. BRowNsTr-:IN 3,301,030

ROTARY STRAIGHTENING MACHINE Raymond G. Browns/ein INVENTOR B-Y W LMQNAT TOR N EYS Jian. 3L H967 R. G. BROWNSTEIN 3,303,03@

ROTARY STRAIGHTENING MACHINE Filed April 7, 1964 5 Sheets-Sheet 2 2/82/0 "4 ATTORNEYS Jan. 31, 967 R. G. BRowNsTl-:IN

ROTARY STRAIGHTENING MACHINE Sigma Filed April '7, 1964 iinited Statespatent Gif-ice 3,3%,03 Patented Jan. 3l, i967 3,301,030 RTARYSTRAIGHTENENG MACHINE Raymond G. Brownstein, 300 Fountain Ave., ElfwoodCity, Pa. 16117 Filed Apr. 7, 1964, Ser. No. 357,893 l0 Claims. (Cl.72-98) This invention relates generally to equipment for automaticstraightening of tubular stock, and is particularly concerned with theprovision of a machine capable of straightening thin wall stock over ashort span through compression forces rather than through a conventionalbending technique.

Tube straightening machines have come into widespread use, particularlyin recent years, and it is common practice at the present time toutilize straightening machines of the type in which a bending operationtakes place in sufficient amount to afford a permanent straightenedstock. These types of machines usually require a relatively long span ofoperation on the tubular stock in order to properly guide the samethrough the bending op eration. To this end, present machines use aplurality of guides and/ or successive spaced rollers which contact thetraveling stock and maintain the same in desired alignment through thestraightening apparatus. Aside from the long span aspects, thesemachines must operate at relatively slow speeds in order to apply theproper bending forces.

It is also conventional practice to exert the bending Vforces `on thetraveling stock at spaced points about the outer periphery of the stockwhile the same is traveling through the apparatus. One of the primarydrawbacks of presently used machines of this type, is the requirementthat the machine be bulky and the stock be of a relatively long spansince it is necessary for the stock to travel between spaced pointswithin the machine and between rotating rollers disposed at differingangles of rotation. With the most widely used form of this type machine,the stock traverses an area in which three different sets of rollersengage the stock at spaced points along the length thereof and bend thesame in different directions thereby straightening the elongate tubularstock.

Notwithstanding the advances which have been made in the tubestraightening field, there remains a need for an efficient `operablestraightening machine capable of straightening tubular stock Within ashort span, and further capable of applying compression forces within aconfined area so that the tubular stock is worked without the need ofstock guides and at a relatively high speed. More particularly, and byway of example rather than limitation, there is a need for a pipestraightening machine, which is capable of accommodating `a wide rangeof stock diameters, which machine operates at relatively high speedswithout the use of auxiliary guide means spaced throughout the machine,and which machine is capable of maintaining constant and controlledpressure on the working rollers so as to afford an even straighteningoperation on the traveling stock.

Bearing in mind the foregoing, it is a general object of the presentinvention to provide a straightening apparatus which meets the aforesaidrequirements, and which is conveniently and efficiently operable tostraighten tubular stock of varying sizes or diameters, and t-oaccommodate varying lengths of tubular stock. Still further, in thisgeneral regard, it is an important object of the present invention toprovide such an apparatus which is capable of efficiently handlingseveral different types of tubular stock, more particularly stock ofdifferent material by compressively operating on the constituentparticle or fiber orientation of the stock to achieve the straighteningthereof.

Consistent with the above general and basic specific objects of theinvention, there are certain more detailed objects thereof, includingthe following:

(a) the provision of an Iapparatus conforming with the preceding objectswherein the elongate tubular stock is engaged about spaced points on theperiphery thereof by at least three rotating surfaces one of whichsurfaces rotates in a direction opposite the direction in which theother two surfaces are rotating;

(b) the provision of an apparatus conforming with the preceding objectswherein the rotating surfaces simultaneously straighten the elongatetubular stock and advance the stock forwardly past the rotatingsurfaces;

(c) the provision `of such an apparatus conforming with the precedingobjects wherein spaced points on one peripheral portion of the elongatetubular stock are progressively engaged with the side working edges andcentral portions of the unitary rotating surface and wherein one side ofthe peripheral portion of the elongate stock is progressively engaged bya a second independent rotating surface disposed in overlying relationto one of the side working edges of the first surface and wherein thissecond rotating surface rotates in a direction `opposite to that of thefirst rotating surface and progressively engaging the other side of theopposite peripheral portion of the elongate stock with a thirdindependent rotating surface which is disposed in overlying relation tothe other side working edges of the rst rotating surface and whereinthis third rotating surface is moved in the same direction as the secondroller surface;

(d) The provision of such an apparatus conforming with the preceding4objects wherein two of the rotating surfaces engaging the elongatetubular stock along spaced points on the periphery thereof are supportedon a pivotallymounted frame which maintains the disposition of both therotating surfaces Iabout an axis making an acute angle with thelongitudinal axis lof the passing elongate tubular stock;

(e) the provision of such an apparatus conforming with the precedingobjects, wherein the engagement of all rotating surfaces upon spacedpoints of the elongate stock are carried out such that any given time,any given cross section of the elongate stock is engaged by the rotatingsurfaces only on the bottom periphery thereof and on one side portion ofthe top periphery thereof;

(f) the provision of such an apparatus conforming with the precedingobjects wherein the rotating surfaces are spaced from one another todefine an elongate tubular stock receiving passageway therebetweenthrough which the elongate stock can pass only by engagement with all ofthe rotating surfaces.

The apparatus provided by the present invention for achieving the abovebasic objects incorporates a main frame or housing upon which ispivotally mounted a pressure roller support frame and a planetary hollowring roller support frame. Each of these frames is provided with aseparate adjustable control mechanism for maintaining both the angularadjustment of the same as well as the pressure under which the rollersand planetary ring are maintained in engagement with the travelingstock. In line with this general arrangement, the invention has certainspecific objects which relate to the overall apparatus design, themanner in which the tubular stock is passed through the straighteningapparatus, the manner in which the straightening apparatus is pivotallymounted on the main or base housing, the manner in which thestraightening operation itself is carried out, and the manner in whichthe apparatus is selectively adjustable depending on the diameter of thetubular stock being straightened thereby.

In more detail, a specific object of the present invention is to providea pipe straightening apparatus conforming with the preceding objectswherein the tubular stock passing through the straightening area ismaintained in contact with a plurality of pressure rollers in such amanner as to properly track the stock through the machine without theuse of auxiliary guides. In other words, in this regard, it is an objectof the present invention to provide an apparatus in 4which thestraightening operation is confined to a limited area and around asingle relatively minor section of the tubular stock at any giveninstant of time.

A second specic object of the present invention is to provide such anapparatus which includes, in addition to the pressure roller and theplanetary hollow ring roller support frames, separate hydraulicallydriven adjustable speed motors for operating the pressure rollers aswell as the planetary hollow ring roller.

A still further object of the present invention is to provide a rotarypipe straightening apparatus having a pressure roller support framewhich is pivotally mounted about its longitudinally extending axisthereby permitting angular adjustment of the pressure rollers withrespect to both the traveling or passing tubular stock and the outerhollow planetary ring roller. In regard to this specific object, it isan additional object of the present invention to provide adjustmentmechanisms for both the pressure rollers and the planetary ring rollerin order to enlarge or reduce the passageway through which tubular stockmay travel for the straightening operation. Following this objectanother step, it is an additional object of the present invention toprovide a hydraulic actuator operated by an adjustable pressure leverfor pivotally moving the pressure roller supporting frame about itsvertical axis and to provide a regulated and adjustable straighteningload, plus a balancing load to counteract the weight of the rollers andframe. Moreover, still another object of the invention in this regard,is to provide a pair of turn wheel actuators and connecting each with aseparate worm gear for meshing the same with a movable or reciprocablerack. By means of the gear and rack arrangement the pressure rollersupporting frame and the planetary ring roller supporting frame arepivotally moved about respective axes.

With respect to the pressure rollers and the straightening operation,still another important specific object of the present invention is toprovide an apparatus which operates in accordance with the precedingobjects, but which includes a pair of pressure rollers mounted forrotatable action about parallel axes disposed at an acute angle withrespect to the axis of rotation of the planetary hollow ring roller.Again, carrying this object one step further, an additional importantspecific object of the present invention is to provide such astraightening apparatus wherein both pressure rollers are mounted on asingle frame and powered by a single hydraulic pressure driven motoralso supported on this frame. In this regard, an additional importantspecific object of the present invention is to provide for the pivotaladjusting movement of the pressure roller support frame with respect tothe planetary hollow ring roller and its convex internal tapered surfaceso as to permit various diameters of tubular stock to be engaged by boththe pressure rollers and the internal tapered surface of the hollowplanetary ring roller.

Another, still further and additional specific object of the presentinvention, is to provide such a straightening apparatus which operatesin accordance with the preceding objects and further includes ahydraulic driving mechanism mounted on the planetary ring rollersupporting frame and which driving mechanism is connected to the ringroller by means of a pulley and a timing belt which is reeved about theouter periphery of the hollow ring roller. In this regard, anotherspecific object of the present invention is to provide a gear shift beltdrive having non-lubricated gear combinations, wherein only the bearingsrequire lubrication.

The invention resides in the combination, arrangement, and constructionof the overall apparatus, as well as in certain subcombinations andarrangements incorporated in the overall machine. The invention will bebetter understood, and objects other than those set forth above willbecome apparent, when consideration is given to the following detaileddescription. Such description makes reference to the annexed drawingspresenting preferred and illustrative embodiments of the invention.

In the drawings:

FIGURE l is a front elevational view of a rotary straightening apparatusconstructed in accordance with the present invention;

FIGURE 2 is a front elevational view of the straightening apparatus ofFIGURE l in reduced scale, but showing parts of the operating mechanismin partial cut-away section;

FIGURE 3 is a top plan view of the apparatus of FIG- URE 2;

FIGURE 4 is a top plan view similar to FIGURE 3, but partially insection and on an enlarged scale;

FIGURE 5 is a partial top plan view of the apparatus of FIGURE 1, butshowing other parts of the apparatus in section;

FIGURE 6 is a sectional side view taken along the line 6--6 of FIGURE 2,showing in detail the mechanism and controls for pivotally operatingparts of the apparatus of FIGURE l;

FIGURE 7 is a schematic sectional view taken along the line 7-7 ofFIGURE 5, showing the passage of an elongate tubular stock through theapparatus.

A machine constructed in accordance with the present invention mayultimately have yan appearance similar to that shown in FIGURE l. Byreferring to such Fig ure, it will be noted that the machine, asgenerally designated by the numeral 2, is supported on a base section 4,The main frame or housing of the straightening machine is generallydesignated by the numeral 6. A pressure roller supporting frame S ismounted on ythe main frame 6 of the straightening machine for bothvertical reciprocal movement and lpivotal movement with respect to thelongitudinal axis of the frame. Also mounted on the main frame 6 is aplanetary ring roller supporting frame 10 which is pivotally supportedon the circular trunnion 12. A pair of turn wheel adjusting screws 14and 16 are also mounted on the main frame 6 of the straightening miachine. These turn wheels 14 and 16, respectively, control the pivotalmovement of the pressure -roller support frame and the planetary ringroller support frame.

A straightening machine such as that shown in FIGURE 1 is adapted tohandle different types of elongate tubular stock of varying diameters.By way of example, the straightening machine 2 can be considered as usedin the handling and straightening of a thin wall tubular stock such asthat designated by the numeral 18. It is to be understood, however, thatthe machine can be used for straightening other types of tubularelongate :stock having thin walls or thick walls and that the thin wallstock devscribed in connection with the straightening machine ispresented merely for exemplary purposes.

By `referring to FIGURE l it will be seen that the pressure rollersupport frame 8 comprises a `pair of parallel vertically disposed andlspaced apart shaft members 2G and 22 having threaded and reduced endportions 24, 26 and 28, 30, respectively. The Adesired spacing of theshafts 20 and 22 is maintained by securing the ends thereof in twoseparate housings 32 and 34. Each of these housings is provided with ahorizontal cross member 36 and 38, respectively, and ya pair of collars46, 52 and 44, 46, respectively. Centrally disposed along the horizontalconnecting bars 36 and 38 are a pair of collars 43 and 50 for engagingythe vertically disposed shafts 52 and 53, respectively. Thesevertically disposed shafts serve las the pivotal axis for angularadjustment of the pressure roller support frame 8. The shafts and 22 aresecured in the housings 32 and 34 by means of the nuts 24', 26', 28 and311'.

Referring to FIGURE 4, it will be seen that each of the vertical shafts211 and 22 supports a two-section collar S6 |and 58, which collars aremounted approximately equidistant from the ends of the respectiveshafts. These collars comprise an outer portion 611 which is fastened tothe inner portion 62 by means of the threaded bolts 64 and 66 incooperation with the nuts designated by the reference numeral 68.Integral with the inner portion 62 of the collars 56 and 58 andextending therebetween is the arm 72. Integral with the collar 56 is anoutwardly extending arm portion 74 similar in structure to the arm 7@integral with the collar Sti.

As more clearly shown in FIGURES 4 and 5, a pressure roller 78 isjournaled between the arm 72 and the extension 35 yand is driven by thehydraulic drive motor 80, supported on the extension 115 of the arm 74.As described below, a second pressure roller 76 is journaled between thearms 7i) and 72, thereby serving the purpose of an idler roller.However, it should be here understood that a hydraulic drive similar tothe motor S0 could easily be provided for the pressure roller 76, if itit were desired to exert greater compressive forces on the passingelongate tubular stock. Thus, for purposes `of explanation anddescription, the single motor drive 80 is described in connection withthe pressure roller 7S.

As seen in FIGURE 4, the convention-al hydraulic drive motor 80 has anoutput drive shaft 82 extending therefrom and journaled in the outerbearing 84. The shaft S2 is rigidly connected to the circular rotatingcolllar 86 at one side thereof (shown in dotted line) and a second driveshaft 88 is connected to the other side of the collar 86 opposite thedrive shaft 82 for transmitting rotating forces thereto. The shaft 3Sextends through the extension 85 of the arm 74 and into a recessed 'area9@ wherein the spindle bearing 92 supports the shaft SS for rotationtherein. The pressure roller 7S has an internal bore 94 therein throughwhich the shaft S8 extends and is then journaled in the arm 72 of thepressure roller support frame. Another bearing 96 is Iprovided in therecess 71 of the arm 72 which accepts the end of the shaft 8S.

In order to maintain proper compressive forces on the passing elongatetubular stock 121, it is necessary to provide a convex face on .thepressure rollers 76 and 78 which engage the stock. The pressure roller76, as discussed above, is shown as an idler roller in the machine ofFIG- URES 4 and 5. However, as also noted above, the same can be drivenin a similar manner as the pressure roller 78. Pressure roller 76 isalso provided with a convex face around the periphery thereof and isjournaled for rotation between the arms 72 and '711 by means lof theshaft 98. A pair of spindle bearings 11111 and 1112 are provided tomaintain proper rotation and alignment lof the pressure roller 76.

As previously mentioned in connection with the description of theoverall straightening apparatus, a rotating peripheral ring roller 104is `mounted on the support frame generally designated by the referencenumeral 1t). This planetary ring roller 104 is disposed in a verticalplan between the shafts 211 and 22 of the pressure roller frame 8. Theplanetary ring roller 1114 is further provided with a V-belt engaginggroove 1116 on one peripher-al edge 105 thereof. The internal periphery1118 of the planetary ring roller 1114 is tapered from a narrow portionon one face thereof, to the wide opening at the outer face around whichthe V-belt groove 106 is disposed. The planetary ring roller 1114 isjournaled for trunnion 12 within the horizontal plane.

rotation within the frame 10 by means of a ring bearing' having ytheroller bearings 112 supported therein. Mounted within the internalperiphery of the planetary ring roller 1114 is a tapered circularsurface 114 having an extending rim portion 116 connected to the recess117 in the planetary ring roller 104 by means of a fastener 118. Thefasteners 118 comprise a plurality of screw threaded bolts 12) andwashers 122 mounted around vthe periphery of the plate 116 as best shownin FIGURE 1. In this manner, it is possible to selectively remove theinternal tapered surfa-ce or roller 114 from the planetary ring roller104 when it is desired .to change the taper or diameter thereof.

A conventional hydraulic drive motor 124 is mounted on the planetaryring supporting frame 11i at the outer end 131 thereof, as best shown inFIGURES 4 and 5. The motor mounting and the drive shaft extensiontherefrom consist of the drive shaft 126 extending outwardly from themot-or housing 124 and journaled in the bearing 131i. The shaft 126 isrigidly connected t0 the circular collar 132 on one side thereof and adrive shaft extension 134 is connected to the other side of the circularcollar 132. The shaft 134 is journaled in the bearings 136 and 13S,thereby maintaining the proper support and alignment -of the driveshaft. At the end 140 of the drive shaft 134 remote from the col-lar 132is la pulley member 142 secured thereto. As seen in FIGURE l, the shaft134 is connected to the pulley member 142 by means of a key 141 and slot143 arrangement. Thus, rapid removal of the pulley from lthe shaft ispossible where desired. By means of pulley member 142, and an endlessV-belt 144 reeved thereabout and extending over the V-notch 1116 of theperipheral ring roller 1114, this ring roller and the cooperatingtapered internal surface 114 are driven thereby. For purposes of safety,a V-belt cover 146 is removably mounted on the planetary ring rollersupport frame 1d, as seen in FIGURE 4. For purposes of better showingthe invention and cooperating structure, the frame 11i in FGURE 1 isshown With the protective cover 146 removed therefrom.

As previously described above, the peripheral ring roller support frame111 is pivotally supported on the trunnion 12 for horizontal pivotalmovement. As seen in FIGURES 4 and 6, the turn wheel 16 is supported byits mounting bar 151i, 151, and connected through a shaft 152 which isprovided with a gearing arrangement 154 for engaging the arcuatelyshaped rack 156 attached to the planetary ring roller support frame 1t).In this manner the frame is pivoted about its vertical axis on the Theshaft 152 is journaled in the support structure and 15S so that rotatingmovement of the same meshes the gear 154 with the arcuate rack 156 onthe planetary ring roller support frame 111. In order to properly guidethe planetary ring r-oller support frame 1t), a forwardly extendingguide member 160 is attached to the front end of the frame 111, as seenin FIGURE 4, and has a downwardly extending arm portion 162 for engaginga slot 164 on the base or main frame 6 of the straightening machine. Theslot 164 is disposed between the removable frame portion 16S attached tothe main frame 6 by means of the bolts and 172 and a recess portion 174rearwardly thereof. Thus, the maximum horizontal movement about thevertical axis upon which the peripheral ring frame 10 may move isdictated by the ends 176 and 17S of the slot164.

The angular disposition of the pressure roller support frame 8 isadjusted in a similar manner to that previously described in connectionwith the angular adjustment of the planetary ring roller support frame10 about its vertical axis. The turn wheel 14 is journaled in thesupports and 182 by means of the extending shaft 184 connected theretoand the ring bearings 186 and 188 which. are laterally spaced from oneanother. In the medial portion of the shaft 184 is disposed a worm gear190 similar to the gear 154 on the shaft 152. This worm gear 190 mesheswith the gear 192 disposed on the arm 194 extending from the horizontalconnector member 38 connecting the two vertical shafts 20 and 22 of thepressure roller supporting frame. By means of this arrangement, it ispossible to turn the entire pressure roller supporting frame 8 about itsvertical axis 50, 52 and there- Iby adjusting the size of the passagewayfor accepting the elongate tubular stock within the planetary ringroller 104.

Depending on the diameter of the tubular stock which is being worked bythe straightening apparatus, the specific location or orientation of thepressure rollers 76 and 78 within the inner contines of the planetaryring roller member 104 and the tapered surface 114 may be adjusted notonly as to its angular disposition about the vertical axis previouslymentioned, but also may be adjusted with respect to the verticaldisposition of the pressure rollers '76 and 78. In this regard,applicant has provided an adjustable stroke air cylinder generallydesignated by the reference numeral 200, shown in FIG- URES 3 and 4.This adjustable stroke air cylinder is of a conventional type commonlyoperating on an air pressure within the range of 75 to 125 p.s.i.a. Thecylinder is enclosed by the main frame or base portion 6 and is suppliedwith air pressure from a source not shown in the drawings. By means of aturn wheel 202 and a vertically depending shaft 204 the operator of thestraightening machine may adjust the desired working air pressure andmaintain the same at a constant level.

Upon actuation of the cylinder 200, a piston 206 is extended downwardlytherefrom. Within the confines of the outer wall of the base section 6 apivoted lever arm 208 is supported on a sliding block 210 by the shaftmember 212 for vertical pivoting movement. At the base of the pressureroller supporting frame 8 and within the base section 6, is disposed ashaft member 214 having the shaft 50 attached to the upper end thereoffor engagement with the horizontal connector arm 38. Consequently, uponactuation of the air cylinder 200 and the extension of the piston 206 aforce is transmitted through the shaft 218 to the lever arm 208 whichpivots about the shaft 212 and thereby exerts an upward force on themember 214 through the shaft 220. This structure is shown in FIGURE 2,in a substantially reduced scale. In this manner, the passageway definedby the surfaces of the pressure rollers 76 Iand 78 and the taperedsurface 114 connected to the planetary ring roller member 104, isselectively adjustable according to the size of the elongate tubularstock which is to be straightened by the present invention. As shown inFIGURE 4, the lever connection 208 between the piston 216 and the member214 at the bottom of the pressure roller frame 8 is disposed in anangular relation with respect to the longitudinal axis of the planetaryring roller support frame 10.

In operation of the rotary straightening machine, described herein, alength of elongate tubular stock which has been generally designated byreference numeral 1S is progressively engaged about spaced points on oneperipheral portion of the stock by the side working edges 113 of theunitary planetary ring roller 114 during its rotation in a iirstdirection by means of the hydraulic motor 124. As stated above, the ringroller is driven through the corresponding drive means connected to thepulley 142 and subsequently the V-belt 144 engaging the V- groove 106 inthe planetary ring roller 104. On the opposite peripheral portion of thestock 18, one of the pressure rollers 76 progressively engages one sideof the stock while the roller is rotating in an overlying relation tothe side working edge of the planetary ring roller and the taperedworking edge 115.

The pressure rollers 76 and 78 are rotated in a common directionopposite to that of the rotation of the planetary ring roller and thetapered surface which partially surround the pressure rollers disposedin the central portion thereof. The axis of rotation of the planetaryring roller 104 and the cooperating tapered surface 114 attached theretomakes an acute angle with the longitudinal axis of the passing stock 18.The axis of rotation of the pressure rollers 76 and 78 makes an acuteangle with the longitudinal axis of the stock 18, which angle has beenfound to produce the most desirable results when of the magnitude ofbetween 5 and 30 degrees. As will be seen from FIGURES 4 and 5, the axisof rotation of the pressure roller 76 is spaced in a parallel relationto the axis of rotation of the pressure roller 78. The roller 78progressively engages the other side portion on the top periphery of thepassing stock and this roller is disposed in overlying relation as wellas to the side edge of the planetary rotating ring roller 104. Each ofthe acute angles defined by the rotating axes of the pressure rollers 76and 78, and the longitudinal Vaxis of the elongate tubular stock 18 areat least substantially of the same magnitude.

The progressive engagement of the rotating surfaces with the passingelongate stock is carried out such that at any given time, any givencross section of the elongate stock is engaged by the rotating surfacesonly on the bottom periphery thereof and one side portion of the topperiphery. The spacing between the rollers 76 and 78 and the workingedges of the tapered surface 114 define the elongate tubular stockreceiving passageway therebetween. It therefore becomes necessary forthe passing stock to engage the rotating ring and both the pressurerollers whenever a straightening operation takes place. Both of thepressure rollers 76 and 78, as previously mentioned, are supported by acommon frame member disposed within the ring member and the shafts ofthe rollers 'I6 and 78 are journaled in opposite faces of the supportframe generally designated by the reference numeral 8.

By means of the various adjusting mechanisms previously described, thespacing between the pressure rollers 76 and 78 and the planetary ringroller member 104 may be adjusted, thereby changing the size of thepassageway to accommodate tubular stock of varying sizes. It should alsobe here noted that the tubular stock is not only straightened during thepassage through the space defined by the rotating surfaces but it isalso rotated by means of its engagement with the rotating surfaces.Consequently, it is possible to assure substantially total engagementand straightening of the tubular stock by the pressure rollers 76 and73, the rotating planetary ring roller member and the cooperatingsurfaces on the internal portion thereof.

In the normal operation of the straightening machine, sutiicientpressure is exerted by the hydraulic cylinder 200 on the pressure rollersupport frame 8 so that constant engagement by the pressure rollers withthe passing elongate tubular stock is maintained. However, in the eventof a possibility of the tubular stock having an irregularity or anexpanded section therein, it is necessary to set the pressure exerted bythe pressure rollers on the tubular stock at a certain predeterminedlevel. Accordingly, a bleeder valve 221 is provided for allowing thepressure rollers '76 and 78 to disengage the tubular stock when thepredetermined value or pressure level is exceeded. For example, thetubular stock passing through the passageway defined by the rotatingsurfaces may have an expanded section therein, which, if the pressure ofthe rollers 76 and 78 was maintained on the stock would damage theserollers and thus require repair or replacement of the same. Therefore,by means of the bleeder valve 221 any increased pressure beyond thepredetermined value causes a pivoting of the support frame 8 about itsvertical axis and thereby allows disengagement of the pressure rollers76 and 78 from the tubular stock 18. In other words, the pressurecontrol means maintains the frame and thereby the pressure rollers inthe given position with respect to the planetary ring roller member andthe tapered surface only so long as the pressure exerted by the passingtubular stock on the pressure rollers is below the predetermined value.

In view of the fact that the straightening operation is carried outwithin the confines of the rotating planetary ring roller and itscooperating tapered surface it is not necessary that a long span oftubular stock be used in order to straighten any portion thereof.Furthermore, the need for adjustable guides is also done away with sincethe passageway defined -by the rotating surfaces is of such smallmagnitude that proper alignment is not critical. By means of the variousadjusting mechanisms previously described in connection with the overallapparatus, it is possible to accommodate tubular stock ranging from onequarter inch to 4 inch ldiameters `with the present straighteningmachine of the instant invention.

As shown in FIGURE 7, the planetary ring roller 104 and the taperedinternal surface 115 are turning or rotating in a clockwise direction asindicated by the arrow 117 while the pressure roller 78 is rotated in acounterclockwise direction as indicated by the arrow 119. Consequently,compressive forces are exerted at spaced points on the periphery of thetubular stock 18, namely at the points 123 and 125, while the same isrotated in a clockwise direction as indicated by the arrow 127. Sincethe showing of FIGURE 7 is a schematic of the sectional view along theline 7-7 of FIGURE 5, the pressure roller 76 is not seen in this view.However, if the same would be shown, it would be spaced vertically andwithin the same horizontal plane as the pressure roller 78, but exertinga compressive force on the passing elongate tubular stock at a spacedpoint from the other roller.

After reading the foregoing description of the preferred andillustrative embodiments of the invention, it should be apparent thatthe objects set forth at the outset of the present specication have beensuccessfully achieved.

Accordingly what is claimed is:

1. Apparatus for straightening alongate tubular stock comprising, incombination:

(a) a hollow ring member having an internal straightening face betweenside working edges thereof;

(b) means supporting said ring member for rotation;

(c) means for driving said ring member;

(d) first roller means;

(e) second roller means;

(f) lmeans for rotatably supporting said rst and second roller means atleast partially within said ring member with said rst roller meansdisposed in overlying relation to one Working edge of said straighteningface and with said second roller means disposed in overlying relation tothe other working edge of said straightening face;

(g) said rst and second roller means being rotatable about parallel axesmaking an acute angle with the axis of rotation of said ring member;and,

(h) said first and second roller means being spaced from one another andfrom said ring member to define an elongate tubular stock receivingpassageway therebetween through which elongate stock can pass only byengagement with said first and second roller means and said ring member.

2. The combination defined in claim 1 wherein said means for rotatablysupporting said lirst and second roller means includes a common supportelement disposed within said ring member, said support element havingone end of each of said roller means journaled in opposite facesthereof.

3. The combination defined in claim 1 wherein said means for rotatablysupporting said rst and second roller means for supporting said ringmember comprises a ring frame and means mounting said ring frame forpivotal movement about an axis disposed perpendicularly to the axis ofrotation of each of said roller means and the axis of rotation of saidring member.

5. The combination dened in claim 4 and further including means forpivotally adjusting at least one of said frames relative to the other.

6. The combination defined in claim 4 and further including first andsecond independently operable adjustment means for respectivelypre-setting the pivotal positions of said roller frame and said ringframe.

7. The combination deiined in claim 3 wherein said means mounting saidroller frame further includes means for adjusting the spacing betweensaid roller means and said ring member so that the size of saidpassageway can be adjustably pre-set to accommodate tubular stock ofvarying size.

8. Apparatus for straightening elongate tubular stock comprising, incombination:

(a) a hollow ring member having an internal convex straightening facebetween side working edges;

(b) means supporting said ring member for rotation;

(c) means for driving said ring member;

(d) irst roller means;

(e) second roller means;

(f) frame means for rotatably supporting said first and second rollermeans at least partially within said ring member with said first rollermeans disposed in overlying relation to one working edge of saidstraightening face and with said second roller means disposed inoverlying relation to the other working edge of said straightening face;

(g) said first and second rollers being rotatable about parallel axesmaking an acute angle with the axis of rotation of said ring member;

(h) said first and second roller -means being arcuately spaced from oneanother and from said ring member to define an elongate tubular stockreceiving passa-geway therebetween through which elongate stock can passonly by engagement with said rst and second roller means and said ringmember;

(i) means for adjustably supporting said frame means for movement withrespect to said ring member whereby the spacing between said rollermeans and said ring member is adjustable; and,

(j) pressure control means for maintaining said frame means and therebysaid roller means in a given position with respect to said ring memberonly so long as the pressures exerted by the stock on said roller meansis below a predetermined value.

9. The combination defined in claim 8 wherein said pressure controlmeans comprises an adjustable pressure sensitive biasing means operablein response to pressure above said predetermined value to permit saidframe means to move to a position increasing the spacing between saidroller means and said ring member.

10. The combination defined in claim 8 wherein said means for adjustablysupporting said frame means includes means mounting said frame means forpivotal movement about an axis disposed perpendicularly to the axis ofrotation of each of said roller means and the axis of rotation of saidring member.

References Cited by the Examiner UNITED STATES PATENTS 577,907 3/1897Wootton 72-98 1,097,281 5/1914 Abramsen 72-98 1,190,698 7/1916 Abramsen72-98 2,163,669 6/'1939 Didden 72-98 CHARLES W. LANHAM, PrimaryExaminer. R. D. GREFE, Assistant Examiner.

1. APPARATUS FOR STRAIGHTENING ELONGATE TUBULAR STOCK COMPRISING, INCOMBINATION: (A) A HOLLOW RING MEMBER HAVING AN INTERNAL STRAIGHTENINGFACE BETWEEN SIDE WORKING EDGES THEREOF; (B) MEANS SUPPORTING SAID RINGMEMBER FOR ROTATION; (C) MEANS FOR DRIVING SAID RING MEMBER; (D) FIRSTROLLER MEANS; (E) SECOND ROLLER MEANS; (F) MEANS FOR ROTATABLYSUPPORTING SAID FIRST AND SECOND ROLLER MEANS AT LEAST PARTIALLY WITHINSAID RING MEMBER WITH SAID FIRST ROLLER MEANS DISPOSED IN OVERLYINGRELATION TO ONE WORKING EDGE OF SAID STRAIGHTENING FACE AND WITH SAIDSECOND ROLLER MEANS DISPOSED IN OVERLYING RELATION TO THE OTHER WORKINGEDGE OF SAID STRAIGHTENING FACE; (G) SAID FIRST AND SECOND ROLLER MEANSBEING ROTATABLE ABOUT PARALLEL AXES MAKING AN ACUTE ANGLE WITH THE AXISOF ROTATION OF SAID RING MEMBER; AND, (H) SAID FIRST AND SECOND ROLLERMEANS BEING SPACED FROM ONE ANOTHER AND FROM SAID RING MEMBER TO DEFINEAN ELONGATE TUBULAR STOCK RECEIVING PASSAGEWAY THEREBETWEEN THROUGHWHICH ELONGATE STOCK CAN PASS ONLY BY ENGAGEMENT WITH SAID FIRST ANDSECOND ROLLER MEANS AND SAID RING MEMBER.